Case Report: Fentanyl Use Associated With Amnesia

MONDAY, Jan. 29, 2018 (HealthDay News) -- Another case of unusual amnestic syndrome that includes bilateral hippocampal lesions on magnetic resonance imaging has been described in a case report published online Jan. 30 in the Annals of Internal Medicine.

Uzoma B. Buru, M.D., from the West Virginia University School of Medicine in Morgantown, and colleagues describe the case of a 30-year-old man with persistent memory impairment. The patient had a history of heroin use and had been abstinent from drugs for more than one month. He was difficult to arouse one morning when found with drug paraphernalia. The patient kept asking repetitive questions and was taken to a hospital.

The researchers found that cocaine was identified in a serum toxicology screen, but urine toxicology test results were negative. Bilateral, symmetrical hypodensities were revealed in the hippocampi and basal ganglia on computed tomography of the brain. There were minimal elevations in serum aspartate and alanine aminotransferase levels. The patient's amnesia was characterized as anterograde at a tertiary medical center. Diffusion-weighted hyperintensities involving all of both hippocampi, the fornices, mammillary bodies, and globus pallidus were identified on magnetic resonance imaging of the brain. Confirmatory urine testing 80 hours after presumed exposure revealed the presence of norfentanyl but was negative for fentanyl. Serum and urine tests for designer opioids, synthetic cannabinoids, buprenorphine, tramadol, and synthetic cannabinoid metabolites were negative.

"To our knowledge this report is the first to associate fentanyl with this amnestic syndrome," the authors write.